The present disclosure herein relates to a pressure sensor and a method for manufacturing the same, and more particularly, to a pressure sensor using a micro electro mechanical system (MEMS) technology and a method for manufacturing the same.
A pressure sensor is a device measuring pressure of gas or liquid. In recent years, a micro electro mechanical system (MEMS) pressure sensor fabricated by using a semiconductor technology is spotlighted because of its miniaturization, low cost, and high performance.
The pressure sensor is classified into a capacitive type pressure sensor and a piezo-resistive type pressure sensor. The piezo-resistive type pressure sensor detects variation of a resistance component according to stress occurrence of a piezo-resistive material provided on an upper portion of a sensing thin film to measure the pressure by deformation of the sensing thin film. The capacitive type pressure sensor detects variation between values of capacitances of a sensing electrode varied by the pressure and a fixed reference electrode to measure the pressure.
A conventional pressure sensor is fabricated by a bulk micromachining and a method for adhering different kinds of substrates. In more detail, a substrate constituting the sensing thin film through the bulk micromachining of the substrate and another substrate for constituting a sealed cavity disposed on an upper or lower portion of the sensing thin film are adhered to each other to fabricate the conventional pressure sensor. In this case, since process compatibility with a circuit unit is low, the circuit unit needs to be separately fabricated.